A nanocomposite includes a matrix material and nanoparticles which have been added to the matrix material to improve a particular property of the material. For example, nanoparticles can be added to materials to keep them lightweight and make them ductile, while simultaneously increasing the strength of the materials. Nanocomposites having high strength-to-weight ratios are of interest to industries, such as the aerospace and automotive industries, provided they can be produced at lower cost with properties comparable to more conventional, heavier materials.
Metal matrix nanocomposites (MMNCs) are a type of nanocomposite in which nanoparticles, such as ceramic nanoparticles, are added to a metal matrix. MMNCs are desirable because they can be made from relatively inexpensive, abundant metals with strengths comparable to those of more expensive alloys. Although MMNCs have the potential for use in many industrial applications, their use has been limited by restrictions in batch size and process development that have hindered the ability to produce MMNCs in industrial-scale quantities.
MMNCs have been produced at the laboratory scale (i.e., in quantities of a few hundred grams or less) using a simple set-up where an ultrasonic probe is inserted into a small crucible containing a molten metal to which nanoparticles have been added. The ultrasonic probe uses cavitation to break-up nanoparticle agglomerates into nanoparticle agglomerates and individual nanoparticles, which are then dispersed within the molten metal. Unfortunately, the quantity of MMNC that can be processed in such a system scales with the probe diameter and it is impractical to scale-up the ultrasonic probe to a size that would allow for industrial-scale production. For this reason, methods for producing MMNCs in industrial-scale quantities based on ultrasonic cavitation have not been developed.